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day 11, cleaner

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Joshua Seigler 2024-12-11 01:15:05 -05:00
parent d5950dd5e9
commit 52437aeb8a
2 changed files with 19 additions and 36 deletions
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4
.aocrunner.json
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@ -162,7 +162,7 @@
"solved": true, "solved": true,
"result": "213625", "result": "213625",
"attempts": [], "attempts": [],
"time": 54.460336 "time": 4.472301
}, },
"part2": { "part2": {
"solved": true, "solved": true,
@ -170,7 +170,7 @@
"attempts": [ "attempts": [
"299307972" "299307972"
], ],
"time": 130.250605 "time": 126.217947
} }
}, },
{ {

51
src/day11/index.ts
View file

@ -2,50 +2,33 @@ import run from "aocrunner"
const parseInput = (rawInput: string) => rawInput.split(' ').map(Number) const parseInput = (rawInput: string) => rawInput.split(' ').map(Number)
function cacheKey(...args) { // good enough const memoize = <T extends unknown[],U>(fn: (...args: T) => U): (...args: T) => U => {
return args.map(String).join('\n'); const cache = {} // Saves the values
}
function memoize<T extends unknown[],U>(fn: (...args: T) => U): (...args: T) => U {
const cache = {}; // Saves the values
return (...args) => { return (...args) => {
const key = cacheKey(...args); const key = args.join('\n')
if (!cache[key]) { // Not in the cache? Call fn. return cache[key] ?? (cache[key] = fn(...args))
cache[key] = fn(...args); // Now it's in the cache.
}
return cache[key];
} }
} }
/** How many stones will a stone marked `n` be after `turn` blinks? */
const count = memoize((n: number, turn: number): number => {
if (turn === 0) return 1
if (n === 0) return count(1, turn - 1)
const digits = Math.floor(Math.log10(n)) + 1
if (digits % 2 === 0) {
const exp = 10**(digits/2)
return count(Math.floor(n / exp), turn - 1) + count(n % exp, turn - 1)
}
return count(n * 2024, turn - 1)
})
const part1 = (rawInput: string) => { const part1 = (rawInput: string) => {
const input = parseInput(rawInput) const input = parseInput(rawInput)
const blink = (n: number, turn: number): number[] => { return input.reduce((total, s) => total + count(s, 25), 0)
if (turn === 0) return [n]
if (n === 0) return blink(1, turn - 1)
const digits = Math.floor(Math.log10(n)) + 1
if (digits % 2 === 0) {
const exp = 10**(digits/2)
return [
...blink(Math.floor(n / exp), turn - 1),
...blink(n % exp, turn - 1)
]
}
return blink(n * 2024, turn - 1)
}
return input.flatMap(s => blink(s, 25)).length
} }
const part2 = (rawInput: string) => { const part2 = (rawInput: string) => {
const input = parseInput(rawInput) const input = parseInput(rawInput)
const count = memoize((n: number, turn: number): number => {
if (turn === 0) return 1
if (n === 0) return count(1, turn - 1)
const digits = Math.floor(Math.log10(n)) + 1
if (digits % 2 === 0) {
const exp = 10**(digits/2)
return count(Math.floor(n / exp), turn - 1) + count(n % exp, turn - 1)
}
return count(n * 2024, turn - 1)
})
return input.reduce((total, s) => total + count(s, 75), 0) return input.reduce((total, s) => total + count(s, 75), 0)
} }